Safety valve for aerosol dispensers



March 17, 1970 w, RIGOR 3,501,067

SAFETY VALVE FOR AEROSOL DISPENSERS Filed Aug. 13. 1968 .8m mvzmon HERBERT W. RIGOR United States Patent 3,501,067 SAFETY VALVE FOR AEROSOL DISPENSERS Herbert W. Rigor, 685 Quartz Way, Broomfield, Colo. 80020 Filed Aug. 13, 1968, Ser. No. 752,377 Int. Cl. B65d 53/06 US. Cl. 222-464 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a magnetic stop valve and permanent magnet actuator therefor that cooperate to prevent children from emptying the contents from an aerosol dispenser. The stop valve automatically plugs the intake end of the tube leading to the dispensing valve as soon as the latter is actuated unless said stop valve is retained in open position by a permanent magnet placed in close proximity thereto on the bottom of the container.

Small children find aerosol dispensers quite fascinating because they are easy to operate and, once the dispensing valve is opened, more exciting things happen that is the case with opening other types of containers. Few mothers of small children have escaped the delightful experience of finding shaving cream, ice cream topping or whipped cream smeared liberally on the children, their clothing,

- playmates and just about everything else within squirting range. More often than not, such an experience is just about as funny as it is serious; however, one need not reflect very long on the subject to realize that this same sort of thing could have tragic consequences. More and more we find highly toxic substances like, for example, insect sprays, open cleaners, metal polishes, etc., being marketed in aerosol dispensers. The very fascination such dispensers have for small children make these products doubly dangerous. Even if the child is lucky enough to avoid taking the toxic substance internally Where death may result, burns and loss or impairment of the eyesight pose very real dangers that can occur quite easily.

It has now been found in accordance with the teaching of the instant invention that accidents such as those outlined above can, in large measure, be eliminated by equipping the conventional aerosol dispenser with an inexpensive safety valve. The valve comprises a lightweight plug normally resting on the bottom of the container with the upset head thereof located in the intake end of the tube leading to the dispensing valve. As soon as the dispensing valve is open, the contents rushing past the head of the plug as they enter the tube raise and seat the plug in the tube so as to prevent further discharge of the contents. Actually, the tube is plugged almost instantly following opening of the discharge valve so that little, if any, of the contents escape. The plug is either formed entirely of some ferrous metal responsive to a permanent magnet or, alternatively, has such a metallic member attached thereto as a separate element. In any event, the plug is rendered responsive to the field of a permanent magnet brought into close proximity thereto on the outside of the container so as to prevent said plug from rising into its seated position when the discharge valve is opened. Thus, unless the permanent magnet has been moved into position to hold the plug in its retracted or unseated open position, the dispenser is left virtually inoperative for all practical purposes.

If the aerosol container itself is fabricated from a ferrous metal, which most of them are, the permanent magnet can be stored elsewhere on the outside surface until needed. Since almost every type of aerosol container includes a delivery tube or the equivalent thereof extending from the dispensing valve down to a point near the bottom on the in- 'lce side thereof, these containers are, for the most part, all capable of being fitted with the safety plug of the present invention without any modification in existing construction.

It is, therefore, the principal object of the present invention to provide a novel safety valve for use with aerosol containers.

A second objective of the invention herein disclosed and claimed is to provide an aerosol container equipped with both the customary dispensing valve and a safety valve, the latter being a valve that has to be held open before the contents can be dispensed.

Another object is to provide an improved aerosol can that is difficult for small children to operate who do not know that secret of releasing the safety valve while, at the same time, being easily operated by an adult or, for that matter, any one apprised of the valve-opening technique.

An additional objective is to provide a container of the type aforementioned that requires no modification other than, perhaps, flaring of the intake end of the delivery tube to accept one particular design of plug.

A further object of the invention is to provide an aerosol container safety valve that is inexpensive, versatile, reliable, compact, rugged, unobstrusive, compatible with any prodnet that can be packed in an uncoated steel can while being easily rendered compatible with those that cannot, and one that does not interfere with normal operation and use of the container when retracted into open position.

Other objects will be in part apparent and in part pointed out specifically hereinafter in connection with the description of the drawings that follows, and in which:

FIGURE 1 is an elevational view of an ordinary dispensing container for aerosols, portions of the body and delivery tube having been broken away and shown in section to better reveal the plug-like valve member seated in the intake end of the latter;

FIGURE 2 is an enlarged fragmentary section showing even more clearly the manner in which the plug-like valve member seats in the intake end of the delivery tube;

FIGURE 3 is enlarged fragmentary section much like FIGURE 2 except that it shows the valve plug held in retracted position against the container bottom by the permanent magnet;

FIGURE 4 is a diametrical section through a slightly modified style of plug having the ferrous metal disk sealed inside the plastic plug rather than being cemented to the outside thereof; and,

FIGURE 5 is a fragmentary section similar to FIGURE 2 showing a further modified tapered plug for use in a delivery tube having the intake end thereof flared.

Referring now to the drawings for a detailed description of the invention, reference numeral 8 has been selected to broadly designate an internally pressurized dispensing container for aerosols of the common type having, in the particular form shown in FIGURE 1, a hollow cylindrical body 10 closed on the lower end by a bottom wall 12 and on top by a cap 14 sealed around a rigid extension 16 of a delivery tube 18, said extension mounting an externally-located dispensing valve 20 at the upper discharge end thereof. Container 8, as illustrated, is intended as being merely representative of the wide variety of shapes, types and styles of such containers in common use today, and no attempt has been made to show the structural details thereof except insofar as certain of its features relate to the placement and operation of the safety valve of the present invention. The latter valve has been designated in a general way by reference numeral 22, and it will be seen to include a permanent magnet 24 and a plug referred to broadly by reference numeral 26.

The delivery tube 18 is, oftentimes, about the same size as that illustrated so as to leave very little space for the plug 26 to seat in its intake end 28. While, undoubtedly, the internal diameters of these tubes vary somewhat with the different manufacturers and, perhaps, even with the various container sizes, most of them seem to run somewhere between 42 inch and inch in inside diameter, with the majority running around inch. In one sense, this is an advantage because it does not take much to plug it up. On the other hand, its size demands that the plug be equally small and delicately made.

The plug 26 of FIGURES 1-4, inclusive, bears an inescapable resemblance to an old-style collar button of the type used with collarless shirts to which detachable collars were fastened. More specifically, it will be seen to include an upset head 30 of more or less circular configuration having a diameter less than the inside diameter of the delivery tube so as to leave a space therebetween for the passage of the pressurized contents as indicated in FIGURE 3 by the arrows. The function of this head is to form a miniature umbrella that will lift the remainder of the plug 26 up and seal the conical seat 32 thereof against the intake end 28 of the delivery tube 18 when the pressurized contents press on its under surface and rush past its peripheral edge. In order to properly perform this function, the head 30 must include an overhanging marginal skirt 34 surround ing the neck 36 that interconnects the head and base 38. With this being the primary function of the head, it becomes readily apparent that it need not be circular, although no advantage would be gained by making it otherwise. Also, as long as a passage is left between the margin of the head and the adjacent wall of the delivery tube for the escape of the contents, it is possible that portions of the head could have nearly the same diameter as the inside of the delivery tube but, here again, it is not seen that any useful purpose would be served by such a construction which would be more complicated and, therefore, more expensive, to say nothing of the greater likelihood it would jam. As to whether the head needs to be made concave on its underside, it doesnt; however, such a construction is preferred due to its better lift characteristics.

The base 38, as aforesaid, has a conical seat 32 formed on its upper surface adapted to seal against the intake end 28 of the delivery tube 18 when elevated into the closed position of FIGURES 1 and 2. The diameter of the base must, therefore, be some greater than the inside diameter of the delivery tube. As shown, base 38 is about the same as the outside diameter of tube 18, although it could, of course, be a good deal larger and still work quite well. Obviously, if the base gets too large, the plug will be so heavy that the pressurized contents pressing against the underside of the head will be unable to lift it into closed position.

The conical shape of the seat 32 is preferred be cause it has a self-centering function that would not come about from a flat planar seat. The flat seat would, of course, work nearly as well, provided it were made Wider by the amount of the maximum gap possible between the head and inside of the tube so as to accommodate lateral shifts of the plug. Once more, we encounter a situation where other configurations can be made to work, but they offer no foreseeable advantage and they have some readily recognizable disadvantages.

Before proceeding further, it should, perhaps, be mentioned that the intake end 28 of tube 18 need not necessarily be chamfered to provide a frusto-conical surface 40 adapted to mate with the conical seat 32 as shown in FIGURES 2 and 3 although, obviously, such a surface is preferably from a sealing standpoint because it results in continuous annular area contact being made. Since these delivery tubes are usually thin-walled and formed from some type of easily deformed plastic, the

pressure on the underside of the plug base when the latter is in closed position is ordinarily adequate to maintain the required seal even though the intake end of the tube is square-cut and produces essentially annular line contact with the seat.

Next, the neck 36 must be of a length such that, with the base 38 resting on the bottom 12 of the container, the head 30 is already slightly up inside the intake end 28 of the delivery tube in the path of the pressurized contents rushing past the edge thereof. Equally important is the fact that, unless the head is always part way up inside the delivery tube, the plug will instantly become disengaged therefrom and completely inoperative.

A look at FIGURES 1 and 3 will quickly reveal that the length of neck 36 is determined by how close the intake end 28 of the delivery tube approaches the bottom 12 of the container. Thus, it becomes much simpler to cut the delivery tubes to the correct length needed to accommodate a particular plug than to vary the length of the plug necks. Cutting these tubes to any desired length is a simple operation to perform prior to installation in the dispensing valve.

The bottom 12 of the container is usually planar in the center where the plug rests as shown in FIGURES 1 and 3 or else convex. Even in those containers having a convex bottom, the curvature thereof across the area covered by the base 38 of the plug is so slight that the underside 42 thereof can remain planar although, of course, there is nothing to prevent its being made concave to conform thereto. While a concave under surface for the base to conform with a convex container bottom would be perferable from the standpoint of the stability of the plug, this advantage would be out-weighed by the difficulties associated with shaping same, especially in a unit like that of FIGURES 2 and 3 where the plug 26 is made of some non-magnetic material to the base 38 of which a ferrous metal disk 44 is cemented or otherwise fastened.

While on this point, the entire plug 26 may be made of a ferrous material which, in itself, is non-magnetic, but which will respond and be attracted by the field of a permanent magnet; or, alternatively, the plug may be made of plastic or some other non-ferrous material and have a ferrous metal disk 44 attached to its base as shown in FIGURES 2 and 3. Another modification is that shown in FIGURE 4 wherein the plug 26m has been modified to have the disk 44m buried inside thereof in sealed relation adjacent the bottom of the base. This construction would find its widest application in those instances where the bare metal of disk 44, along with the interior surfaces of the can, might contaminate the contents unless covered by an appropriate coating. Conversely, it is possible that the contents might attack the disk and container, thus requiring them to be coated or otherwise protected.

Briefly, with regard to the modification shown in FIG- URE 5, the delivery tube 18m has been altered slightly to include a flared intake end 28m. This can, of course, be accomplished quite easily in the case of most plastic tubes by merely slipping same over a heated tapered mandrel of some sort to produce the required flare. The flare has the advantage of providing a greatly-enlarged intake opening which will, in turn, accommodate a larger plug 26n.

Plug 2611, instead of resembling a collar button as was the case before, has more of a miniature Christmas tree shape in that the head 30m thereof is more or less bluntlypointed at the top and flares downwardly and outwardly therefrom to define skirt 34m which, in this instance, must have a diameter greater than the inside of the. delivery tube 18m even at the flared throat or intake end 28m thereof because the seat 32m now forms a part of the head 30m and not the base 38m.

Since the 'base 38m no longer carries the seat 32m, its sole remaining functions are to provide a stop limiting the extent to which the head can drop down and open up the intake end of the delivery tube, a base upon which the plug rests when in open position, and a surface to either carry the ferrous metal disk 44 as shown or, itself, pro vide the ferrous surface within the field of the permanent magnet 24 when the latter is on the underside of the container bottom.

In the particular form shown, the neck 36m merges with the base 38m so as to be indistinguishable therefrom. Since the base does not carry the seat 32m in this version of the plug, it need not be larger than the flared surface 40m on the intake end of the delivery tube, nor does it have to have any special shape. In fact, an item like a metal thumbtack stuck axially up into the underside of the modified head 30m would suffice to replace the neck 36m, base 38m and even the disk 44, while giving the plug a shape even more closely resembling a miniature Christmas tree.

The seat 32m has been shown to have a downwardly and outwardly flared configuration rather than a true conical one, although either shape will suffice nicely for this purpose. This flared seating surface 32m cooperates with a similar, but less pronounced, flare 40m on the intake end of the delivery tube to produce the continuous annular seal therebetween and also center the plug in the latter.

Disk 44 is shown attached to the underside of base 38m, although it could be sealed therein as was the case with the FIGURE 4 version. Also, the entire plug 2621 could, if desired, be made entirely of a ferrous metal so as to eliminate disk 44 altogether; however, in this instance, the plug can be considerably larger due to the flared end of the delivery tube 18m, and the much greater weight of the larger metal plug might make it diflicult to lift into closed position by the pressurized contents flowing therepast Finally, it would seem appropriate to provide a few words of explanation concerning the operation of the safety valve described above. The normal position of the plug 26 is resting on the bottom 12 of the container 8 so as to leave the intake end of the delivery tube open. Note that at this point the magnet 24 is stored elsewhere on the can, such as on the top as shown in FIGURE 1, and the plug is held in open osition by gravity alone. Now, the instant that dispensing valve 20 is actuated to open delivery tube 18 to the atmosphere through its rigid extension 16, the positive pressure inside the container tends to equalize with the atmosphere, thus forcing the contents into the intake end 28 of the delivery tube. As the contents impinge against the underside of the overhanging umbrella-like skirt 34 of the head 30, it lifts the plug up into closed position where the seat 32 thereof forms an annular seal against the intake end of the delivery tube. From a practical standpoint, the plug need not seal perfectly in the end of the delivery tu'be because any of the contents that move up into the delivery tube past an imperfect seal can only escape during the t me the dispensing valve is also actuated to open position, and this is likely to be for a very 'brief period when nothing comes out. In other words, the little material that might escape past the safety valve would certainly not encourage the user to hold the dispensing valve open for very long; hence, the seal it makes need not be perfect because it is normal- 1y backed up by the dispensing valve seal.

Now, when the time comes to actually dispense the contents, the magnet is placed on the bottom 12 of the container so that the field thereof envelops disk 44 to hold the plug 26 in open position. This operation must be done with the dispensing valve close-d because the magnetic field will not be strong enough to pull the plug down into open position from a closed position with the contents flowing therepast. It will, however, hold the plug open due to the much closer proximity of the disk 44 and its position in the stronger portions of the magnetic field. Thus, with the magnet in the position shown in FIGURE 3, the dispensing container can be operated just as if it was not equipped with the safety valve of the present invention.

Having thus described the several useful and novel features of the present invention in connection with the accompanying drawings, it will be apparent that the many worthwhile objectives for which it was designed have been achieved. Although only what are believed to be the preferred embodiments of the safety valve for aerosol dispensers have been illustrated and described, I realize that certain changes and modifications therein may well occur to those skilled in the art within the broad teaching hereof; hence, it is my intention that the scope of protection afforded hereby shall be limited only insofar as said limitations are expressly set forth in the appended claims.

What is claimed is:

1. The dispensing container for aerosol-s which comprises: a hollow body closed at opposite ends by a top and bottom to provide a fluid-tight vessel; a delivery tube sealed in the top with its discharge end on the outside and its intake end of the inside spaced above the bot-tom; a dispensing valve on the discharge end of the delivery tube operative upon actuation to open the latter and release the contents when the intake end is open; plug means movable between a closed position blocking the intake end of the delivery tube and an open position resting on the bottom so as to unplug the latter, said plug means including a magnetic base responsive to the field of a permanent magnet placed in close proximity thereto, a head having an end portion projecting up into the intake end of the delivery tube in both open and closed positions and a skirt portion overhanging the base, and an annular seat carried by one of said base and head elements, said skirt portion being responsive to the movement of the contents against the underside thereof with the discharge valve open to raise the plug means from open into closed position, and said annular seat being adapted to seal the intake end of the delivery tube with the plug means in closed position; and, a permanent magnet movable into position on the underside of the bot-tom and operative when so positioned to attract the base and hold the plug means in open position while the dispensing valve is open to release the contents.

2. The dispensing container for aerosols as set forth in claim 1 in which: the annular seat comprises an upwardly and inwardly tapered surface of the head.

3. The dispensing container for aerosols as set forth in claim 1 in which: the head is smaller than the delivery tube at the intake end thereof so as to permit the contents to flow therepast; and, the annular seat comprises an upwardly and inwardly tapered surface of the base.

4. The dispensing container for aerosols as set forth in claim 1 in which: the plug means is fabricated from a nonmagnetic metal responsive to the field of a permanent magnet.

5. The dispensing container for aerosols as set forth in claim 1 in which: the plug means is fabricated from a non-magnetic material; and, means comprising a metal element of non-magnetic material responsive to the field of a permanent magnet is fastened to the base.

6. The dispensing container for aerosols as set forth in claim 1 in which: the skirt comprises an integral annular undercut flange bordering the head along the lower margin thereof.

7. The dispensing container for aerosols as set forth in claim 1 in which: the intake end of the delivery tube is flared and adapted to form a continuous annular seal with the seat.

8. The dispensing container for aerosols as set forth in claim 2 in which: the intake end of the delivery tube is flared to form a continuous annular seal with the tapered surface of the head.

9. The dispensing container for aerosols as set forth in claim 3 in which: the intake end of the delivery tube is chamfered to mate with the tapered surface of the base.

7 8 10. The dispensing container for aerosols as set forth 3,848,543 10/ 1967 Stafford 251-65 X in claim 5 in which: the metal element is sealed Within the 2,743,078 4/ 1956 Jordan 2 5 1-65 base of the plug so as to leave no portion thereof exposed to the contents. SAMUEL F. COLMAN, Primary {Examiner References Cited 5 N. L. STACK, J R., Assistant Examiner UNITED STATES PATENTS U S Cl XR. 2,785,838 3/1957 Mayer 222464 X 3,050,219 8/1962 Sa'garin et a1. 25165 X ZZZ-39,4 251-65 

